1. Technical Field
The present invention relates to a nozzle check pattern and a liquid droplet ejection apparatus that ejects liquid droplets to form the nozzle check pattern.
2. Related Art
Inkjet recording apparatuses that eject ink from nozzles to record an image are known as liquid droplet ejection apparatuses. Among inkjet recording apparatuses, there are apparatuses provided with the function of checking the ejection status of each nozzle by recording a nozzle check pattern.
In inkjet recording apparatuses, inkjet recording heads are becoming increasingly denser and disposed with increasingly more nozzles in accordance with increases in speed and improvements in picture quality in recording apparatuses of recent years.
Further, numerous inkjet recording apparatuses of the full width array (FWA) format, which can record an image equal to the width of a page at once, have been proposed. In the case of such inkjet recording apparatus, there are also apparatuses where the number of nozzles disposed in the inkjet recording heads is several thousand.
There are various causes of defects in nozzles of the inkjet recording format, such as contamination with foreign matter and air bubbles, hardening of ink, electrical failure, and the lifespan of actuators. Yet if the rates of occurrences of defects in individual nozzles are the same, the rate of occurrences of defects in the nozzles of an inkjet recording apparatus tends to increase in accordance with increases in the number of nozzles.
At the same time, in response to increases in the rate of occurrences of defects in the nozzles, numerous methods have been proposed which identify defective nozzles and minimize, with image processing, deterioration in image quality even when ejection defects in nozzles occur. Assuming that ejection defects of several nozzles are allowed, the advantages are great, such as reducing costs resulting from a rise in the yield of inkjet recording heads and extending the lifespan of inkjet recording heads.
When such image processing is conducted, it is crucial to identify the nozzles in which ejection defects have occurred, and a method of easily and accurately identifying nozzles in which ejection defects have occurred is needed.